Molecular design of self-coacervation phenomena in block polyampholytes.

Autor:	Danielsen SPO; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106.; Materials Research Laboratory, University of California, Santa Barbara, CA 93106., McCarty J; Materials Research Laboratory, University of California, Santa Barbara, CA 93106.; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106., Shea JE; Materials Research Laboratory, University of California, Santa Barbara, CA 93106.; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106.; Department of Physics, University of California, Santa Barbara, CA 93106., Delaney KT; Materials Research Laboratory, University of California, Santa Barbara, CA 93106; ghf@ucsb.edu kdelaney@ucsb.edu., Fredrickson GH; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106; ghf@ucsb.edu kdelaney@ucsb.edu.; Materials Research Laboratory, University of California, Santa Barbara, CA 93106.; Materials Department, University of California, Santa Barbara, CA 93106.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2019 Apr 23; Vol. 116 (17), pp. 8224-8232. Date of Electronic Publication: 2019 Apr 04.
DOI:	10.1073/pnas.1900435116
Abstrakt:	Coacervation is a common phenomenon in natural polymers and has been applied to synthetic materials systems for coatings, adhesives, and encapsulants. Single-component coacervates are formed when block polyampholytes exhibit self-coacervation, phase separating into a dense liquid coacervate phase rich in the polyampholyte coexisting with a dilute supernatant phase, a process implicated in the liquid-liquid phase separation of intrinsically disordered proteins. Using fully fluctuating field-theoretic simulations using complex Langevin sampling and complementary molecular-dynamics simulations, we develop molecular design principles to connect the sequenced charge pattern of a polyampholyte with its self-coacervation behavior in solution. In particular, the lengthscale of charged blocks and number of connections between oppositely charged blocks are shown to have a dramatic effect on the tendency to phase separate and on the accessible chain conformations. The field and particle-based simulation results are compared with analytical predictions from the random phase approximation (RPA) and postulated scaling relationships. The qualitative trends are mostly captured by the RPA, but the approximation fails catastrophically at low concentration. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
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